Actuator having an address selector

ABSTRACT

A system incorporating an actuator connected to a polarity-insensitive two-wire communications bus. The actuator may have an electromechanical mover, a processor connected to the electromechanical mover, and a potentiometer, having a number of address settings, connected to the processor. A setting of the number of settings of the potentiometer may be a selection of an address for the actuator on the communications bus. There may be additional actuators and a controller connected to the communications bus. Each actuator may have an address which is different from an address of the other actuators connected to the communications bus. If an actuator is substituted with a replacement actuator, then a setting of a plurality of settings on a potentiometer of the replacement actuator may be selected to obtain an address that is the same as the address of the actuator which is substituted.

BACKGROUND

The present disclosure pertains to control devices and particularly tomechanical movers of devices. More particularly, the disclosure pertainsof actuators.

SUMMARY

The disclosure reveals a system incorporating an actuator connected to apolarity-insensitive two-wire communications bus.

The actuator may have an electromechanical mover, a processor connectedto the electromechanical mover, and a potentiometer, having a number ofaddress settings, connected to the processor. A setting of the number ofsettings of the potentiometer may be a selection of an address for theactuator on the communications bus. There may be additional actuatorsand a controller connected to the communications bus. Each actuator mayhave an address which is different from an address of the otheractuators connected to the communications bus. If an actuator issubstituted with a replacement actuator, then a setting of a pluralityof settings on a potentiometer of the replacement actuator may beselected to obtain an address that is the same as the address of theactuator which is substituted.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a diagram of an example layout of actuators and a controllerconnected to a common bus;

FIG. 2 is a diagram of actuators connected to a controller via a bus andto a roof top unit;

FIG. 3 is a diagram of an auxiliary switch setpoint control approach;

FIG. 4 is a diagram of an actuator, an economizer and sensor connectedto one another via a bus;

FIG. 5 is a diagram of front and back sides of an actuator revealingcertain knobs for control and adjustment such as an address selectorbeing accessible from both sides;

FIG. 6 is a diagram that shows perspective views of two sides of anactuator revealing the reversibility of actuator position for access toa selector from two sides of the actuator;

FIG. 7 is a diagram of a close view of a selector or mode switch showingpositions available for a test mode and addresses of an actuator;

FIG. 8 is a diagram of a two-wire polarity-insensitive bus controlledactuator;

FIG. 9 is diagram of another layout of another actuator;

FIGS. 10 a through 10 r are schematics of circuitry for the actuator asrepresented by FIG. 9.

DESCRIPTION

Coupled actuators may be used within heating, ventilating andair-conditioning (HVAC) systems. They may drive final control elements.Example applications may incorporate volume control dampers, mounteddirectly to the drive shaft of the actuator or remotely with the use ofaccessory hardware, rotary valves such as ball or butterfly valvesmounted directly to the actuator drive shaft, and linear stroke or cagevalves mounted with linkages to provide linear actuation. The actuatormay also be used to operate ventilation flaps, louvers and otherdevices. The actuator may be a spring return device designed forclockwise or counterclockwise fail-safe operation with a continuouslyengaged mechanical spring. The spring may return the actuator or themechanism that the actuator is operating to a fail-safe position withina certain time of power loss. An example of the certain time may be 25seconds. The actuator may be mounted to provide clockwise orcounterclockwise spring return by flipping or turning the unit over. Thestroke of the actuator may be adjusted for an application at hand. Anauxiliary knob may be used to control minimum position or switchposition. For switch position, a degree of rotation may be selected forwhere the switch is desired to activate. The actuator may have anoverride of the control signal for certain applications such as forexample freeze protection. The override may move the actuator to a fullopen or full closed position. One instance of position change is thatthe actuator may be designed to respond to direct digital control (DDC)instantaneous contact closures.

FIG. 1 is a diagram of an example layout of actuators 41, 42, 43, 44 and45 connected to a common bus 46. Bus 46 may be connected to a controller47. Controller 47 may be Spyder controller. Bus 46 may be a Sylk bus.The actuators may be Zelix actuators. Each actuator may have its openand close speeds individually set by controller 47 via signals on bus46.

For examples of various settings, actuator 41 may have a speed set to a90 second timing, actuator 42 a speed set to a 30 second timing;actuator 43 a speed set to a 30 second timing for opening and a 90second timing for closing, actuator 44 a speed set to a 60 second timingfor a normal mode and a 30 second timing for an emergency mode, andactuator 45 a speed set for a 180 second timing. The speeds each of theactuators may be set to different timings. When a speed of an individualactuator is set by controller 47, the respective actuator may beselected according to its address. Fir instance, actuators 41, 42, 43,44 and 45 may have addresses 11, 12, 13, 14 and 15, respectively.

FIG. 2 is a diagram of actuators 41 and 42 connected to controller 47via bus 46. Actuators 41 and 42 may have connections to a roof top unit(RTU) 48. Actuator 41 may have a variable frequency drive control outputof 2 to 10 volts along lines 51 to a component 53 at RTU 48. Actuator 42may have an auxiliary output binary 24 volts along lines to a component54 of RTU 48.

A present actuator with an auxiliary output may be adjustable vianetwork communications. Auxiliary (aux) switches on actuators in some ofthe related art may have their setpoints established locally on theactuator. Setting an auxiliary switch setpoint may be rather difficultbecause of an actuator location (e.g., in a ceiling or behind equipment)and in general auxiliary switch setpoint user interfaces may bedifficult to set and see (e.g., cam systems, rotating assemblies andadjustable detents) which could lead to setpoint inaccuracies. Also,there may be a fixed hysteresis with each of these solutions.

An additional problem with some of the solutions in the related art isthat they are not necessarily adjustable as a relevant applicationchanges. For example, an aux switch may be set to make or break ataround 45 degrees of the actuator's stroke. If set for 45 degrees, theaux switch may virtually always trip at that position and can notnecessarily be changed without a service technician physically changingthe setpoint. Some applications would benefit by having the aux switchmake at 20 degrees while opening, and break at 60 degrees while closing,or 20 degrees during a heat mode and 45 degrees during a cool mode, orvice versa.

Also, some of the aux switches of the related art may only be able tochange state based on an actuator shaft position. There may be manyapplications where switching the aux switch based on temperature or someother variable (or combination of variables) would be beneficial.

The present approach may solve the issues by allowing the auxiliaryswitch setpoint and control parameters to be configured remotely overthe bus in real time. This approach may be implemented with digital oranalog outputs and there could be a multiple setpoint per relaysolution.

The present approach may be effected by enhancing the software in thecontroller and communicating actuator systems. It may be used byallowing the auxiliary switch parameters to be programmable via a higherorder controller. An example may incorporate using a Jade controller orSpyder™ controller with Niagara™ (or fishsim™) to program thefunctionality of a Sylk™ Zelix™ communicating actuator over a Sylk bus.A Sylk bus may be a two-wire, polarity insensitive bus that may providecommunications between a Sylk-enabled actuator and a Sylk-enabledcontroller. An example of the Sylk bus circuitry may be disclosed inU.S. Pat. No. 7,966,438, issued Jun. 21, 2011, and entitled “Two-wireCommunications Bus System”. U.S. Pat. No. 7,966,438, issued Jun. 21,2011, is hereby incorporated by reference.

FIG. 3 is a diagram of an auxiliary switch control approach. Symbol 11may indicate an auxiliary position change which may be initiated. Anauxiliary switch setpoint may be controlled manually by an auxiliarypotentiometer in symbol 12. Symbol 13 indicates that if the currentactuator position is greater than the setpoint set by the auxiliarypotentiometer, then the auxiliary switch may be activated. If not, thenthe auxiliary switch may be deactivated. Alternatively, in symbol 14,the auxiliary switch setpoint may be controlled by an externalcontroller command. Symbol 15 indicates that if the current actuatorposition is greater than the setpoint set by an external controllercommand, then the auxiliary switch may be activated. If not, then theauxiliary switch may be deactivated.

A present communicating actuator may have a network adjustable runningtime. Applications in the field may require or benefit from differentrunning time actuators. In the related art, different running timeactuators might be purchased by model number, or programmable actuatorsmay be programmed at commissioning using an independent tool. Thissituation may dictate that a person pick one running time for theactuator and application at the beginning of an implementation of theactuator.

An example of an issue of running time may occur during system checkoutin an OEM factory or in the field. An OEM or field technician may prefera fast running time (10 seconds) so that the actuator system can bechecked out quickly without having to wait for a 90 second actuator torun its time.

The present approach may incorporate an actuator that allowsprogrammable running time via the local bus. Over the bus, theactuator's running time may be programmed to different values atdifferent times during the actuator's lifecycle. For example, theactuator may be programmed for 15 second timing during a test, 30 secondtiming during a normal application mode, and 90 second timing during asaver mode.

The present actuator approach may be applied in a Jade™ economizer/SylkZelix system implementation. The Sylk bus hardware may be implemented onthe controller and the actuator. Then the firmware in these products maybe created to implement the adjustable running time functionality.

FIG. 4 is a diagram of a Zelix actuator 21 with Jade economizer 22connected to the actuator via a Sylk bus 23. A sensor 24 may beconnected into the Sylk bus.

A present approach may incorporate a potentiometer address selection foran actuator. Setting a network address on a communicating actuator maybe rather difficult. The actuator may be typically located in a hard toreach area (e.g., in a ceiling or behind equipment). Related artapproaches may involve actuators that are typically small and hard tosee and actuate (e.g., with dip switches/rotary encoders) and may usebinary techniques as described herein which may require multiplemicrocontroller input pins.

The present approach may solve the issue by using a potentiometer to setand establish a network address on a communication actuator. Theapproach may allow for an address selector to be accessible from bothsides of the actuator using a single potentiometer, the numbers andinterface to be large and easy to read, and it may allow the address tobe selected using only one analog input on the microcontroller.

FIG. 5 is a diagram of a front view 31 of an actuator 33 and a back view32 of the actuator. Certain knobs for control and adjustment such as anaddress selector 34 may be accessible from both sides of actuator 33.Selector 34 may have five positions for address selection. For instance,a position 1 may be for selecting an address 11, position 2 for address12, position 3 for address 13, position 4 for address 14 and position 5for address 15. A position 6 may be for selecting a test mode.

FIG. 6 is a diagram that shows perspective views of sides 31 and 32 ofactuator 33 revealing the reversibility of the actuator for access toselector 34 from both sides of actuator 33.

The present approach may incorporate an actuator which has accessibleonboard diagnostics. An issue in the related art may be that actuatorsin the field can fail or malfunction and of which many cases may beundetected. Such actuators may be wasting energy or giving up comfortfor years before the failure is found.

The present approach may solve this issue by communicating alarms,status and diagnostics automatically over a bus. If an actuator fails,an alarm may be sent to the higher order controller for immediatenotification. These software alarms and diagnostic features may beimplemented in the firmware for a Sylk Zelix communicating actuator.

A controller or processor may provide on the communications bus one ormore diagnostics items of a group consisting of high temperaturewarning, excessive noise on power line, record/report back electromotiveforce (EMF) on spring return, percentage of life detection, high amountof travel for given amount of time, hunting around a given point,actuator angle, communication normal indicator, stroke limiting, controlvalve (Cv) selection, flowrate on pressure independent control valve(PIC-V), set auxiliary switch, report auxiliary switch setting, reportauxiliary switch status, report auxiliary switch current draw—auxiliaryequipment status, if switch drives fan—verify fan shuts down beforedamper closes, if switch drives coils—verify heat exchanger runningbefore opening/closing valve, report stuck valve/damper, PIC-V constantpressure—constant torque, changeover valve—no cycling for a period oftime, time since last movement, date/time of first operation(commissioning), audible/detectable signal for location, device inwarranty, device model number/serial number/date code, devicetype—outside air damper/standard ball valve/PIC-V valve/mixed airdamper, actuator fitness/self-test routine—known system conditions,sensor—actual damper/valve position, super capacitor status, and energyconsumption.

The present approach may incorporate an actuator test mode. There may beseveral approaches used by an actuator installer to verify that anactuator has been installed correctly. One approach may involve anoperator at the control panel to cause the actuator to open and close.In another approach, the installer or maintainer may have access theconnector and short the modulating input to cause the actuator to open,thus verifying that the actuator is working and connected properly.

With the test mode, there may be a test mode selection on a pot orswitch that causes the actuator to move to its open position. Aninstaller or maintainer may then just select Test Mode via the pot andverify an operation of the actuator without needing to access theconnector or to communicate with a control operator. Actuator softwaremay verify that the test mode has been selected on the switch orpotentiometer. The software may then exercise the following algorithm.

IF Test Mode THEN

Set actuator speed to maximum allowable speed

Cause actuator to open (move to end of its allowable span)

Remain in this position while in Test Mode.

FIG. 7 is a diagram of a closer view of the selector or mode switch 34,showing 6 positions available for the test mode of actuator 33. A modeplate 35 indicates that position 6 may be designated for “Test” or testmode. Positions 1-5 indicate five different addresses available forselection by switch 34.

FIG. 8 is a diagram of a two-wire polarity-insensitive bus (i.e., Sylk)controlled actuator 61. An electric motor 62 may drive a gear train 63which turn an actuator shaft 64 which may move a damper, valve, or othercomponent. A processor 65 may be connected to motor 62 and providecontrol of the motor. Processor 65 may also be connected to acommunications bus 66. A shaft position potentiometer 67 may bemechanically connected to the actuator shaft 64 or a part on the geartrain to electrically provide a position of shaft 64 to processor 65. Anauxiliary switch output 68 and an analog output 69 may be provided byprocessor 65. A user interface 71 may provide a bus address select toprocessor 65. A user interface 72 may provide a manual auxiliary switchtrigger select. Actuator 61 may be connected to other devices 73 such asactuators, sensors, controllers, and so on. Actuator 61 may have a powersupply 74 to power its components. An AC power line 75 or other sourcemay provide power to supply 74.

FIG. 9 is a diagram of an actuator 120. Many components of actuator 120are revealed in the diagrams shown in FIGS. 10 a through 10 r .Interconnections of the components may be indicated in the diagrams asidentified by various connections and wires having labels andalphanumeric symbols. For example, a line identified as Al in FIG. 10 amay be connected to a line identified as A1 in FIG. 10 b. A processor101 may be connected to power supply electronics 105, bus electronicsand isolation transformer 109, a motor control 103 and a shaft positionindicator 102. Processor 101 may also be connected to an auxiliaryswitch 108, an auxiliary switch and position potentiometer 110, and auser address and auxiliary switch selector 107. Further, processor 101may be connected to an analog out 106 and functional test electronics104.

A motor 112 may be connected to motor control 103. An output of motor112 may be mechanically connected to a gear reduction train 113. Geartrain 113 may have an actuator coupling or shaft 114 for connection to amechanically controlled or operated device 115 such as, for example, adamper, valve, flap, louver, and so on. Gear train 113 may be connectedto shaft position indicator 102.

Bus electronics and isolation transformer 109 may be connected to acommunications bus 116. Outside actuator 120, bus 116 may be connectedto controllers 117, sensors 118, actuators 119, and other devices 121and various communication media 122. An outside power source 123 may beconnected to power supply electronics.

Processor 101 may be shown in a diagram of FIG. 10 a. Shaft positionindicator 102 may be shown in a diagram of FIG. 10 b. Motor control 103may be shown in diagrams of FIGS. 10 c, 10 d and 10 e. Functional testelectronics may be shown in a diagram of FIG. 10 f. Power supplyelectronics may be shown in diagrams of FIGS. 10 g and 10 h. Analog outelectronics 106 may be shown in diagrams of FIGS. 10 i and 10 j. Useraddress and auxiliary switch circuitry 107 may be shown in diagrams ofFIG. 10 k. Auxiliary switch circuitry 108 may be shown in a diagram ofFIG. 10 l. Communications bus electronics 109 may be shown in diagramsof FIGS. 10 m, 10 n, 10 o and 10 p. Auxiliary switch and positionpotentiometer circuitry 110 may be shown in a diagram of FIG. 10 q.Miscellaneous circuitry 125, such as thermistor, oscillator and flashelectronics may be in diagrams of FIG. 10 r. Some of the other Figuresnoted herein may show diagrams of other portions of circuitry helpful inbuilding the actuator system.

The following is a recap of the present actuator system. An actuatorsystem for a heating, ventilating and air conditioning (HVAC) system,may incorporate an HVAC actuator, and a communications bus connected tothe actuator. The actuator may have an electromechanical mover, aprocessor connected to the electromechanical mover, and a potentiometer,having a plurality of address settings, connected to the processor. Asetting of the plurality of settings of the potentiometer may be aselection of an address for the actuator on the communications bus.

The system may further incorporate one or more additional actuatorsconnected to the communications bus. Each actuator may have an addresswhich is different from an address of the other actuators connected tothe communications bus. If the actuator is substituted with areplacement actuator, then a setting of a plurality of settings on apotentiometer of the replacement actuator may be selected to obtain anaddress that is the same as the address of the actuator which issubstituted. The system may also incorporate a controller connected tothe communications bus. The communications bus may have twopolarity-insensitive wires.

The controller may override a setting of the plurality of settings ofthe potentiometer which is a selection of an address for the actuatorand select another or the same address for the actuator via thecommunications bus. An address may define an actuator in terms of one ormore items of a group consisting of an activation program, actuatorstroke speeds, one or more sensor outputs, input/output requirements,slot assignment on the communications bus, one or more parameters of theactuator, and sensor prioritization.

The system may further incorporate a housing that encloses the actuator.Access to the potentiometer for making or changing a selection of anaddress may be available on at least two places of the housing. The atleast two places of the housing may reveal visible indications andphysical features for manual making or changing a selection of anaddress on the potentiometer.

An actuator system for a heating, ventilating and air conditioningsystem, may incorporate a gear train having an HVAC actuator outputshaft coupling, a motor mechanically connected to the gear train, anactuator processor connected to the motor, a potentiometer having aselected value from a plurality of values, connected to the actuatorprocessor, and a communications bus connected to the actuator processor.The selected value from the plurality of values of a potentiometer maybe an address of the actuator processor on the communications bus. Othervalues from the plurality of values besides the selected value may beother addresses for actuator processors on the communications bus. Aselected value of the potentiometer as the address may be an analoginput to the actuator processor.

The potentiometer may be a voltage divider for a selection of the analoginput from various values available for an analog input indicating anaddress. The analog input may be converted into a digital input at theprocessor. A replaced gear train, motor, actuator processor andpotentiometer with a substitute gear train, motor, actuator processorand potentiometer may incorporate selecting a value on the substitutepotentiometer which is the same value on the replaced potentiometer sothat the substitute actuator processor has an address which is the sameas the address of the replaced processor on the communications bus.

The actuator system may further incorporate a housing that encloses thegear train, motor, actuator processor and potentiometer. Thepotentiometer may be accessible on at least two places of the housingfor selecting a value on the potentiometer to be an address of theactuator processor on the communications bus. The communications bus mayhave two polarity-insensitive wires.

An approach for establishing an address for an actuator in a heating,ventilating and air conditioning system, may incorporate setting anaddress for a processor of an HVAC actuator on a communications bus byproviding an input to the processor, connecting the processor to amotor, and connecting the motor to a gear train having an HVAC actuatorshaft coupling. The input to the processor may be provided by aselection on a potentiometer. The potentiometer may have a plurality ofselections having different inputs to the processor. The differentinputs may provide different addresses for the processor on thecommunications bus. The actuator shaft coupling may mechanically operatean apparatus in a heating, ventilating and air conditioning system.

This approach may further incorporate enclosing the processor, themotor, the gear train having the actuator shaft coupling, and thepotentiometer in a housing. The housing, enclosing the processor, themotor, the gear train having the actuator shaft coupling, and thepotentiometer, may be regarded as the actuator. Access to thepotentiometer for selecting an address may be available at two or moreplaces on the housing.

The approach may further incorporate replacing the actuator with asecond HVAC actuator, and setting the potentiometer of the secondactuator to an address that is the same as an address of the replacedactuator. The approach may yet further incorporate selecting an addressfor the processor via a controller and the communications bus. Thiscommunications bus may be a polarity-insensitive two-wire system.

In the present specification, some of the matter may be of ahypothetical or prophetic nature although stated in another manner ortense.

Although the present system and/or approach has been described withrespect to at least one illustrative example, many variations andmodifications will become apparent to those skilled in the art uponreading the specification. It is therefore the intention that theappended claims be interpreted as broadly as possible in view of therelated art to include all such variations and modifications.

What is claimed is:
 1. An actuator system for a heating, ventilating andair conditioning (HVAC) system, comprising: an HVAC actuator; and acommunications bus connected to the actuator; and wherein: the actuatorcomprises: an electromechanical mover; a processor connected to theelectromechanical mover; and a potentiometer, having a plurality ofaddress settings, connected to the processor; and a setting of theplurality of settings of the potentiometer is a selection of an addressfor the actuator on the communications bus.
 2. The system of claim 1,further comprising: one or more additional actuators connected to thecommunications bus; and wherein each actuator has an address which isdifferent from an address of the other one or more additional actuatorsconnected to the communications bus.
 3. The system of claim 2, whereinif the actuator is substituted with a replacement actuator, then asetting of a plurality of settings on a potentiometer of the replacementactuator is selected to obtain an address that is the same as theaddress of the actuator which is substituted.
 4. The system of claim 3,further comprising a controller connected to the communications bus. 5.The system of claim 4, wherein the communications bus comprises twopolarity-insensitive wires.
 6. The system of claim 4, wherein thecontroller can override a setting of the plurality of settings of thepotentiometer which is a selection of an address for the actuator andselect another or the same address for the actuator via thecommunications bus.
 7. The system of claim 1, wherein an address definesan actuator in terms of one or more items of a group consisting of anactivation program, actuator stroke speeds, one or more sensor outputs,input/output requirements, slot assignment on the communications bus,one or more parameters of the actuator, and sensor prioritization. 8.The system of claim 1, further comprising: a housing that encloses theactuator; and wherein access to the potentiometer for making or changinga selection of an address is available on at least two places of thehousing.
 9. The system of claim 8, wherein the at least two places ofthe housing reveal visible indications and physical features for manualmaking or changing a selection of an address on the potentiometer. 10.An actuator system for a heating, ventilating and air conditioning(HVAC) system, comprising: a gear train having an HVAC actuator outputshaft coupling; a motor mechanically connected to the gear train; anactuator processor connected to the motor; a potentiometer, having aselected value from a plurality of values, connected to the actuatorprocessor; and a communications bus connected to the actuator processor;and wherein: the selected value from the plurality of values of apotentiometer is an address of the actuator processor on thecommunications bus; and other values from the plurality of valuesbesides the selected value can be other addresses for actuatorprocessors on the communications bus.
 11. The actuator system of claim10, wherein a selected value of the potentiometer as the address is ananalog input to the actuator processor.
 12. The actuator system of claim11, wherein: the potentiometer is a voltage divider for a selection ofthe analog input from various values available for an analog inputindicating an address; and the analog input is converted into a digitalinput at the processor.
 13. The actuator system of claim 10, wherein areplaced gear train, motor, actuator processor and potentiometer with asubstitute gear train, motor, actuator processor and potentiometercomprises selecting a value on the substitute potentiometer which is thesame value on the replaced potentiometer so that the substitute actuatorprocessor has an address which is the same as the address of thereplaced processor on the communications bus.
 14. The actuator system ofclaim 13, further comprising: a housing that encloses the gear train,motor, actuator processor and potentiometer; and wherein thepotentiometer is accessible on at least two places of the housing forselecting a value on the potentiometer to be an address of the actuatorprocessor on the communications bus.
 15. The system of claim 10, whereinthe communications bus comprises two polarity-insensitive wires.
 16. Amethod for establishing an address for an actuator in a heating,ventilating and air conditioning (HVAC) system, comprising: setting anaddress for a processor of an HVAC actuator on a communications bus byproviding an input to the processor; connecting the processor to amotor; and connecting the motor to a gear train having an HVAC actuatorshaft coupling; and wherein: the input to the processor is provided by aselection on a potentiometer; the potentiometer has a plurality ofselections having different inputs to the processor; the differentinputs provide different addresses for the processor on thecommunications bus; and the actuator shaft coupling can mechanicallyoperate an apparatus in a heating, ventilating and air conditioningsystem.
 17. The method of claim 16, further comprising: enclosing theprocessor, the motor, the gear train having the actuator shaft coupling,and the potentiometer in a housing; and wherein the housing, enclosingthe processor, the motor, the gear train having the actuator shaftcoupling, and the potentiometer, is regarded as the actuator.
 18. Themethod of claim 17, wherein access to the potentiometer for selecting anaddress is available at two or more places on the housing.
 19. Themethod of claim 17, further comprising: replacing the actuator with asecond HVAC actuator; and setting the potentiometer of the secondactuator to an address that is the same as an address of the replacedactuator.
 20. The method of claim 16, further comprising: selecting anaddress for the processor via a controller and the communications bus;and wherein the communications bus is a polarity-insensitive two-wiresystem.